If you’re an average pot smoker in Colorado — paying average prices for average-quality marijuana — you can expect to spend around $650 on weed next year.

A study conducted by the Colorado Futures Center at Colorado State University aimed to get to the bottom of how much the state can expect to collect in tax revenue, now that marijuana is legal. By doing a little extra math, we can get a rough estimate for what the average marijuana enthusiast will spend annually as well.

Researchers estimate that in 2014, 642,772 Colorado residents, or about 12.5% of the state population, will take advantage of pot’s newly legal status. Analysts assumed each person would smoke or otherwise use 3.53 oz. (100 g) of marijuana annually, for a total of 2,268,985 oz. (about 64,320 kg) per year.

All of these numbers may be underestimated, because they’re based on data compiled when recreational marijuana was illegal. In fact, there are so many unknowns in the realm of legal nonmedicinal pot that all of this math has a crude back-of-the-napkin quality to it. In any event, using the study’s numbers, the average marijuana enthusiast can expect to pay a retail price of $185 per oz. next year. Multiply that times 3.53 oz. — which no one can buy at once, mind you, because there’s a 1-oz. (28 g) purchase maximum for residents — and the total comes to $653 annually spent on pot.

How much the individual actually winds up spending on marijuana will depend on several factors, most obviously the quality (and price) of the pot and how much one smokes. Researchers used the crowdsourcing site Price of Weed to get the $185-per-oz. figure. As of early April, an ounce of marijuana was averaging $206 on the black market, and because the price is expected to drop once pot is legal, the study landed on $185. If the smoker is opting for higher-quality, $300-per-oz. marijuana, his annual pot bill would top $1,000. That’s for someone smoking the average of 3.53 oz. per year. A heavy smoker who goes with $300-per-oz. pot and uses, say, half an ounce monthly could expect to drop $1,800 annually on his habit.

That may sound like a lot. But a pot-smoking habit is probably cheaper than a cigarette-smoking habit. Colorado is one of the cheaper states for cigarettes, but a pack still goes for around $5.19, according to one state-by-state price-check compilation. So a one-pack-per-day habit — purchased one pack at a time, not by the carton — comes to $1,894 for a year.

Health officials say once medical expenses and things like lost productivity due to the effects of smoking are incorporated, an addiction to cigarettes is far more costly than that. For that matter, plenty of arguments have been made that legalizing marijuana will result in increased usage and addiction, as well as higher rates of driving while stoned, so the costs to society outweigh any benefits that arise from approving the drug for recreational use.

Oh, and about the point of the Colorado State study, regarding tax revenue for the state? Researchers estimate that the 15% excise tax on wholesale marijuana would yield $21.7 million annually, which is far short of the $40 million annual target. To hit the target, marijuana would have to cost a lot more than the prices that have been estimated, or people in Colorado would have to buy a lot more marijuana than the forecasts project. Neither is likely to occur, the study states. “As competition forces growers and sellers to be more efficient, margins will erode, and both wholesale cost and retail prices are forecast to fall,” the report reads. And instead of usage rising year after year, the study’s authors foresee a “decline in the rate of growth of consumption as the ‘wow’ factor erodes over time, and any marijuana tourism begins to decline, particularly if other states follow Colorado and Washington and legalize marijuana.”